Using complex coacervation for lysozyme encapsulation by spray-drying

The purpose of this study is to evaluate the properties of encapsulated lysozyme (at 0.714 g/L concentration) by spray-drying as well as the effect of complexation with increased pectin concentrations (0-4 g/L) on the preservation of lysozyme structure and activity. Maximum turbidity of spray-dried complexes was lower than unprocessed ones at a threshold pectin concentration above which turbidity was reduced. This result could be attributed to the formation of more individual complexes with decreased aggregation upon application of spray-drying due to configurational changes of the complexes. At higher pectin concentrations (above 0.5 g/L), spray-dried complexes exhibited lower antimicrobial activity compared with unprocessed complexes probably because of high limitation in diffusion and accessibility of substrate to active sites of the encapsulated enzyme within the polysaccharide network. Conformational changes of lysozyme and formation of complexes with pectin upon spray-drying were determined by using fluorescence and UV-Vis absorption measurements. The results revealed that spray-drying had a significant effect on lysozyme structure, activity, and mobility particularly at higher pectin concentrations (above 0.5 g/L).